In the conventional draft device as shown in FIG. 9, when top roller shafts 1', 2' and 3' of back, middle and front top rollers 1, 2 and 3 are supported, the centers of the shafts are pivoted on a cradle 4 and the respective rollers are located on both the sides of the cradle, and the cradle per se is supported at one point 5 with a shaft 6 and the free end 7 of the cradle is elastically pressed toward bottom rollers, whereby a nip pressure is produced between the top rollers 1, 2 and 3 and the corresponding bottom rollers (not shown).
However, in the case where the draft cradle 4 is supported only at the rear end portion 5, slight shaking at the fulcrum is enlarged at the front portion 7, and therefore, a precise space cannot be maintained between the top rollers 3 and the bottom roller (not shown) and the nip pressure between the two rollers can be maintained at a predetermined level.
While, since the roller shafts 1', 2' and 3' are pivoted at the central portions thereof on the cradle and the left and right ends of the shafts 1', 2' and 3' are kept in the free state, shaking is sometimes caused in the roller shafts 1', 2' and 3'. Moreover, there has been an undesirable phenomenon in which when the drafting operation is stopped and a draft cradle is lifted up, an apron which is mounted to surround top rollers and tensers supported on the draft cradle is set in the deformed state at the position having abutting contact with the tensers by long-time stoppage and it is impossible to perform uniform drafting on resumption of the drafting operation.